Reorganize Terraform files

Rename "tf-general" directory to "openstack" since it only discusses OpenStack. Update README.md.

Signed-off-by: Scott Lowe <scott.lowe@scottlowe.org>

terraform/README.md

@@ -4,6 +4,8 @@ This folder contains materials for working with Terraform.
 
 ## Contents
 
-**tf-general:** This directory provides an example Terraform configuration (in both Terraform format as well as JSON format) designed to work with OpenStack.
-
 **aws**: This directory contains a number of different examples of using Terraform with AWS. Refer to the `README.md` in this folder for more details.
+
+**oci:** This directory contains a sample Terraform configuration that illustrates how to work with Oracle Cloud Infrastructure (OCI) using the Terraform OCI provider.
+
+**openstack:** This directory provides an example Terraform configuration (in both Terraform format as well as JSON format) designed to work with OpenStack.